arch/powerpc/mm/pgtable_64.c

   1 /*
   2  *  This file contains ioremap and related functions for 64-bit machines.
   3  *
   4  *  Derived from arch/ppc64/mm/init.c
   5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6  *
   7  *  Modifications by Paul Mackerras (PowerMac) (paulus@samba.org)
   8  *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
   9  *    Copyright (C) 1996 Paul Mackerras
  10  *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
  11  *
  12  *  Derived from "arch/i386/mm/init.c"
  13  *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
  14  *
  15  *  Dave Engebretsen <engebret@us.ibm.com>
  16  *      Rework for PPC64 port.
  17  *
  18  *  This program is free software; you can redistribute it and/or
  19  *  modify it under the terms of the GNU General Public License
  20  *  as published by the Free Software Foundation; either version
  21  *  2 of the License, or (at your option) any later version.
  22  *
  23  */
  24
  25 #include <linux/config.h>
  26 #include <linux/signal.h>
  27 #include <linux/sched.h>
  28 #include <linux/kernel.h>
  29 #include <linux/errno.h>
  30 #include <linux/string.h>
  31 #include <linux/types.h>
  32 #include <linux/mman.h>
  33 #include <linux/mm.h>
  34 #include <linux/swap.h>
  35 #include <linux/stddef.h>
  36 #include <linux/vmalloc.h>
  37 #include <linux/init.h>
  38 #include <linux/delay.h>
  39 #include <linux/bootmem.h>
  40 #include <linux/highmem.h>
  41 #include <linux/idr.h>
  42 #include <linux/nodemask.h>
  43 #include <linux/module.h>
  44
  45 #include <asm/pgalloc.h>
  46 #include <asm/page.h>
  47 #include <asm/prom.h>
  48 #include <asm/lmb.h>
  49 #include <asm/rtas.h>
  50 #include <asm/io.h>
  51 #include <asm/mmu_context.h>
  52 #include <asm/pgtable.h>
  53 #include <asm/mmu.h>
  54 #include <asm/uaccess.h>
  55 #include <asm/smp.h>
  56 #include <asm/machdep.h>
  57 #include <asm/tlb.h>
  58 #include <asm/eeh.h>
  59 #include <asm/processor.h>
  60 #include <asm/mmzone.h>
  61 #include <asm/cputable.h>
  62 #include <asm/ppcdebug.h>
  63 #include <asm/sections.h>
  64 #include <asm/system.h>
  65 #include <asm/iommu.h>
  66 #include <asm/abs_addr.h>
  67 #include <asm/vdso.h>
  68 #include <asm/imalloc.h>
  69
  70 unsigned long ioremap_bot = IMALLOC_BASE;
  71 static unsigned long phbs_io_bot = PHBS_IO_BASE;
  72
  73 #ifdef CONFIG_PPC_ISERIES
  74
  75 void __iomem *ioremap(unsigned long addr, unsigned long size)
  76 {
  77         return (void __iomem *)addr;
  78 }
  79
  80 extern void __iomem *__ioremap(unsigned long addr, unsigned long size,
  81                        unsigned long flags)
  82 {
  83         return (void __iomem *)addr;
  84 }
  85
  86 void iounmap(volatile void __iomem *addr)
  87 {
  88         return;
  89 }
  90
  91 #else
  92
  93 /*
  94  * map_io_page currently only called by __ioremap
  95  * map_io_page adds an entry to the ioremap page table
  96  * and adds an entry to the HPT, possibly bolting it
  97  */
  98 static int map_io_page(unsigned long ea, unsigned long pa, int flags)
  99 {
 100         pgd_t *pgdp;
 101         pud_t *pudp;
 102         pmd_t *pmdp;
 103         pte_t *ptep;
 104
 105         if (mem_init_done) {
 106                 pgdp = pgd_offset_k(ea);
 107                 pudp = pud_alloc(&init_mm, pgdp, ea);
 108                 if (!pudp)
 109                         return -ENOMEM;
 110                 pmdp = pmd_alloc(&init_mm, pudp, ea);
 111                 if (!pmdp)
 112                         return -ENOMEM;
 113                 ptep = pte_alloc_kernel(pmdp, ea);
 114                 if (!ptep)
 115                         return -ENOMEM;
 116                 set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
 117                                                           __pgprot(flags)));
 118         } else {
 119                 /*
 120                  * If the mm subsystem is not fully up, we cannot create a
 121                  * linux page table entry for this mapping.  Simply bolt an
 122                  * entry in the hardware page table.
 123                  *
 124                  */
 125                 if (htab_bolt_mapping(ea, ea + PAGE_SIZE, pa, flags,
 126                                       mmu_virtual_psize))
 127                         panic("Can't map bolted IO mapping");
 128         }
 129         return 0;
 130 }
 131
 132
 133 static void __iomem * __ioremap_com(unsigned long addr, unsigned long pa,
 134                             unsigned long ea, unsigned long size,
 135                             unsigned long flags)
 136 {
 137         unsigned long i;
 138
 139         if ((flags & _PAGE_PRESENT) == 0)
 140                 flags |= pgprot_val(PAGE_KERNEL);
 141
 142         for (i = 0; i < size; i += PAGE_SIZE)
 143                 if (map_io_page(ea+i, pa+i, flags))
 144                         return NULL;
 145
 146         return (void __iomem *) (ea + (addr & ~PAGE_MASK));
 147 }
 148
 149
 150 void __iomem *
 151 ioremap(unsigned long addr, unsigned long size)
 152 {
 153         return __ioremap(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED);
 154 }
 155
 156 void __iomem * __ioremap(unsigned long addr, unsigned long size,
 157                          unsigned long flags)
 158 {
 159         unsigned long pa, ea;
 160         void __iomem *ret;
 161
 162         /*
 163          * Choose an address to map it to.
 164          * Once the imalloc system is running, we use it.
 165          * Before that, we map using addresses going
 166          * up from ioremap_bot.  imalloc will use
 167          * the addresses from ioremap_bot through
 168          * IMALLOC_END
 169          *
 170          */
 171         pa = addr & PAGE_MASK;
 172         size = PAGE_ALIGN(addr + size) - pa;
 173
 174         if (size == 0)
 175                 return NULL;
 176
 177         if (mem_init_done) {
 178                 struct vm_struct *area;
 179                 area = im_get_free_area(size);
 180                 if (area == NULL)
 181                         return NULL;
 182                 ea = (unsigned long)(area->addr);
 183                 ret = __ioremap_com(addr, pa, ea, size, flags);
 184                 if (!ret)
 185                         im_free(area->addr);
 186         } else {
 187                 ea = ioremap_bot;
 188                 ret = __ioremap_com(addr, pa, ea, size, flags);
 189                 if (ret)
 190                         ioremap_bot += size;
 191         }
 192         return ret;
 193 }
 194
 195 #define IS_PAGE_ALIGNED(_val) ((_val) == ((_val) & PAGE_MASK))
 196
 197 int __ioremap_explicit(unsigned long pa, unsigned long ea,
 198                        unsigned long size, unsigned long flags)
 199 {
 200         struct vm_struct *area;
 201         void __iomem *ret;
 202
 203         /* For now, require page-aligned values for pa, ea, and size */
 204         if (!IS_PAGE_ALIGNED(pa) || !IS_PAGE_ALIGNED(ea) ||
 205             !IS_PAGE_ALIGNED(size)) {
 206                 printk(KERN_ERR "unaligned value in %s\n", __FUNCTION__);
 207                 return 1;
 208         }
 209
 210         if (!mem_init_done) {
 211                 /* Two things to consider in this case:
 212                  * 1) No records will be kept (imalloc, etc) that the region
 213                  *    has been remapped
 214                  * 2) It won't be easy to iounmap() the region later (because
 215                  *    of 1)
 216                  */
 217                 ;
 218         } else {
 219                 area = im_get_area(ea, size,
 220                         IM_REGION_UNUSED|IM_REGION_SUBSET|IM_REGION_EXISTS);
 221                 if (area == NULL) {
 222                         /* Expected when PHB-dlpar is in play */
 223                         return 1;
 224                 }
 225                 if (ea != (unsigned long) area->addr) {
 226                         printk(KERN_ERR "unexpected addr return from "
 227                                "im_get_area\n");
 228                         return 1;
 229                 }
 230         }
 231
 232         ret = __ioremap_com(pa, pa, ea, size, flags);
 233         if (ret == NULL) {
 234                 printk(KERN_ERR "ioremap_explicit() allocation failure !\n");
 235                 return 1;
 236         }
 237         if (ret != (void *) ea) {
 238                 printk(KERN_ERR "__ioremap_com() returned unexpected addr\n");
 239                 return 1;
 240         }
 241
 242         return 0;
 243 }
 244
 245 /*
 246  * Unmap an IO region and remove it from imalloc'd list.
 247  * Access to IO memory should be serialized by driver.
 248  * This code is modeled after vmalloc code - unmap_vm_area()
 249  *
 250  * XXX  what about calls before mem_init_done (ie python_countermeasures())
 251  */
 252 void iounmap(volatile void __iomem *token)
 253 {
 254         void *addr;
 255
 256         if (!mem_init_done)
 257                 return;
 258
 259         addr = (void *) ((unsigned long __force) token & PAGE_MASK);
 260
 261         im_free(addr);
 262 }
 263
 264 static int iounmap_subset_regions(unsigned long addr, unsigned long size)
 265 {
 266         struct vm_struct *area;
 267
 268         /* Check whether subsets of this region exist */
 269         area = im_get_area(addr, size, IM_REGION_SUPERSET);
 270         if (area == NULL)
 271                 return 1;
 272
 273         while (area) {
 274                 iounmap((void __iomem *) area->addr);
 275                 area = im_get_area(addr, size,
 276                                 IM_REGION_SUPERSET);
 277         }
 278
 279         return 0;
 280 }
 281
 282 int iounmap_explicit(volatile void __iomem *start, unsigned long size)
 283 {
 284         struct vm_struct *area;
 285         unsigned long addr;
 286         int rc;
 287
 288         addr = (unsigned long __force) start & PAGE_MASK;
 289
 290         /* Verify that the region either exists or is a subset of an existing
 291          * region.  In the latter case, split the parent region to create
 292          * the exact region
 293          */
 294         area = im_get_area(addr, size,
 295                             IM_REGION_EXISTS | IM_REGION_SUBSET);
 296         if (area == NULL) {
 297                 /* Determine whether subset regions exist.  If so, unmap */
 298                 rc = iounmap_subset_regions(addr, size);
 299                 if (rc) {
 300                         printk(KERN_ERR
 301                                "%s() cannot unmap nonexistent range 0x%lx\n",
 302                                 __FUNCTION__, addr);
 303                         return 1;
 304                 }
 305         } else {
 306                 iounmap((void __iomem *) area->addr);
 307         }
 308         /*
 309          * FIXME! This can't be right:
 310         iounmap(area->addr);
 311          * Maybe it should be "iounmap(area);"
 312          */
 313         return 0;
 314 }
 315
 316 #endif
 317
 318 EXPORT_SYMBOL(ioremap);
 319 EXPORT_SYMBOL(__ioremap);
 320 EXPORT_SYMBOL(iounmap);
 321
 322 void __iomem * reserve_phb_iospace(unsigned long size)
 323 {
 324         void __iomem *virt_addr;
 325
 326         if (phbs_io_bot >= IMALLOC_BASE)
 327                 panic("reserve_phb_iospace(): phb io space overflow\n");
 328
 329         virt_addr = (void __iomem *) phbs_io_bot;
 330         phbs_io_bot += size;
 331
 332         return virt_addr;
 333 }